泛型Map的遍历

map的遍历取得的值的顺序与map本身的类型有关。

（1）这种是按照哈希值输出的

（2）这种是按照map存放顺序输出的

Map<String,String> map2 = new LinkedHashMap<String,String>();map2.put("mx_internal_uid","E3F5D833DC2D30C035EC55EBE000A374");map2.put("name", "硝酸盐氮");map2.put("num", "234");Set<String> keys2 = map2.keySet();for (String key2 : keys2) {    System.out.println(key2);}System.out.println("-------------------------");Iterator key2 = keys2.iterator();while (key2.hasNext()){    System.out.println(key2.next());}